A suspected Islamic State militant was arrested from Thane district of India's western Maharastra state on Friday. The suspect, Rizwan Khan, was arrested last night in a joint operation by police of southern Kerala state and Maharashtra Anti-Terrorism Squad (ATS).

He was produced in a Mumbai court today, which sent him to a transit remand till July 25. His lawyer, IO Khan, said that Rizwan was innocent and has been kept in custody, illegally.

"Since last three to four days he is in illegal custody. Why they have taken illegal custody to him, that we cannot say right now. Let's see on 25th, they will produce him before the appropriate court in Ernakulam. So, we will see and definitely he is absolutely innocent. He has nothing to do with the matter," said the lawyer.

This is the second arrest by Kerala police in the last few days, who have been camping in Mumbai over the last week. Earlier this week, Kerala police arrested 45-year-old Arshid Qureshi, a public relation manager with controversial preacher Zakir Naik's Islamic Research Foundation, from Mumbai for allegedly radicalising youth and recruiting them to Islamic State.

Islamic State has struggled to win over recruits in India, which is home to the world's third-largest Muslim population. Indian police arrested 29 men last year for establishing bases to recruit men to the Islamist militant group. All men were charged with conspiracy to wage war against the state.

A handful of Indians are also suspected of having travelled to Iraq and Syria to join Islamic State, where the group is fighting to install an Islamic caliphate.